Spikes:

Separate staminate (male) and pistillate (female) spikes, with usually a single staminate spike up to 2 inches long at the tip of the stem, occasionally with 1 or 2 much smaller staminate spikes just below it. Below the staminate spikes are 2 or 3 (occasionally 4) stalked pistillate spikes, oval to cylindric, up to 2½ inches long, initially erect and often close together near the staminate spikes, typically becoming widely separated at maturity with the lower spikes spreading to drooping. At the base of the lowest pistillate spike is a leaf-like bract that over-tops the terminal spike.

Leaves and stems:

Leaves are basal and alternate, mostly near the base, 2 to 5 mm wide, arching and usually longer than the flowering stem. Stem leaf sheaths are U to nearly V-shaped at the tip, translucent whitish, and loosely wrap the stem. The ligule (membrane where the leaf joins the sheath) is as long as or longer than wide. Leaves are hairless though rough along the edges.

Bases are wrapped in a sheath that is brown to purplish-red and fibrous, forming ladder-shapes of thread-like fibers across the front (ladder fibrillose). Stems are 3-sided in cross-section, smooth but slightly rough near the flowering spikes, initially erect to ascending, often becoming arching to nearly prostrate at maturity. Stems elongate up to 4 feet at maturity and are usually over-topped by the leaves. Plants form dense tufts and may create small colonies from short rhizomes.

Fruit:

Fruit develops in late spring to mid-summer, the pistillate spikes forming clusters of seeds (achenes), each wrapped in a casing (perigynium), subtended by a scale. Perigynia are ascending to spreading and more or less crowded on the spike. Each pistillate spike contains 10 to 30 fruits.

Pistillate scales are lance to egg-shaped, white to light brown with a green midrib, tapering to a pointed tip, awnless, toothless, hairless, narrower and about half as long as the perigynia but mostly hidden by it. Perigynia are 7 to 10 mm long, 4.5 to 7 mm wide, green to brownish at maturity, thin-walled, smooth and shiny, strongly 7 to 12-veined, much inflated, teardrop shaped but flattish on the inner side, broadest at the base, tapering to a long, slender beak that has 2 teeth at the tip. Achenes are 3-sided, 3 to 4 mm long, maturing to brown, crimped along one side with a deep indent in the middle of one angle, and a long, persistent style contorted near the base.

Notes:

Carex tuckermanii reaches the western edge of its range in Minnesota and is a common sedge in the north central and northeastern counties, found in floodplains, forested swamps, alder thickets, and less often along shores and in wet meadows.

Carex is a large genus, with over 600 species in North America and 150+ in Minnesota alone. They are grouped into sections, the species in each group having common traits. Carex tuckermanii is in the Vesicariae section; some of its common traits are: clump forming or not, rhizomatous, hairless leaves, basal sheaths brown or red-purple, sheaths often splitting into fibers and forming a ladder shape, sheaths with cross partitions between veins (septate-nodulose), 2 to 10 spikes, terminal spike all-staminate, leaf-like bract subtending the lowest pistillate spike, perigynia mostly ascending to spreading, hairless, mostly egg to teardrop shaped, beaked and toothed, at least slightly inflated, achenes 3-sided in cross-section with a persistent style.

Carex tuckermanii is distinguished from all other Minnesota sedges by the combination of: 2 to 4 pistillate spikes that are thick-cylindric, the lowest on slender stalks that are typically spreading to drooping and widely separated from the spike above it, up to 30 fruits per spike, perigynia much inflated, 7 to 10 mm long, strongly veined with a long, slender beak, 3-sided achenes pinched on one side and a long, contorted, persistent style, and growing in dense clumps. When the upper pistillate spikes are more crowded together, it has been mistaken for Carex intumescens, which has larger perigynia (10 mm or more long) with a much more gradual taper to the beak. It may also be confused with other members of the Vesicariae section, most notably Carex vesicaria, which has somewhat smaller (7mm long or less) and less inflated perigynia, proportionately longer scales, and up to 100 perigynia per spike. C. tuckermanii is more inflated and rather wider than the other sedges, and the indented achene is a trait shared only with Carex crinita and Carex gynandra in Minnesota.